It has recently been discovered that certain mixed metal oxide materials exhibit high-temperature superconductivity. See, for example, Wu et al, Physical Review Letters, Vol. 58, No. 9, pages 908-910 and Moodenbaugh et al, Physical Review Letters, Vol. 58, No. 18, pages 1885-1887. Specifically, various mixed metal oxide materials comprising rare earth metal oxides, alkaline earth metal oxides and copper oxides have been discovered to exhibit high temperature superconductivity. The rare earth oxide-alkaline earth oxide-copper oxide superconductor materials are generally of the formula
RBa.sub.2 Cu.sub.3 O.sub.7-x where x is less than or equal to 1. Because the superconducting transition temperature T.sub.c of such materials is greater than 77.degree. K., these mixed oxide materials have an increasing number of promising technological applications.
However, the ceramic nature of the superconductor materials poses a number of problems for the manufacture of high T.sub.c superconducting shaped products such as magnetic levitation components and magnetic shielding devices. Additionally, because the mixed oxide superconducting materials are susceptible to degradation by moisture and chemicals such as reducing agents, their use in various applications is limited.